Rocker arms are used in a variety of applications to transmit movement. For example, in certain internal combustion engine designs, rocker arms transmit motion to open and close the engine's valves for the admission of air and the expulsion of exhaust gases. An engine rocker arm system may operate with cam-in-block engines using push rods, in engines with overhead cams, or in engines with camless valve actuation. Rocker arm assemblies use a rocker arm shaft as the locating element and as the reciprocating rotational motion wear surface for the rocker arm. The shaft extends through an opening in the rocker arm dictating size requirements for the rocker arm structure and imposing constraints on rocker ratio options. Reciprocating motion of a rocker arm on the shaft inherently results in limited rotation of the mating surfaces under a constant load, which inhibits lubrication. Motion of a rocker arm may be driven by a camshaft that has lobes to open the valves. Manufacturability constraints on grinding the camshaft lobes limits that range of valve rates that are achievable. In addition, high loads may result on lifters, rocker arms and valves when aggressive lift in needed.